title: Quantification of median lobe protrusion and its impact on the base surgical margin status during robot-assisted laparoscopic prostatectomy.
abstract: OBJECTIVE
  Protrusion of the median lobe (PML) is thought to add technical difficulty during robot-assisted laparoscopic prostatectomy (RALP). Thus, we quantified PML using preoperative magnetic resonance imaging (MRI) and evaluated its impact on base surgical margin (BSM) status during RALP.
  
  
  METHODS
  The clinical data of consecutive patients who underwent RALP were retrieved from a prospectively registered database. Of the 655 eligible men, 9 patients were excluded because they did not undergo MRI. PML was measured in a T2-weighted mid-sagittal scan. We performed univariate and multiple logistic regression analyses.
  
  
  RESULTS
  The mean PML was 8.3 ± 3.6 mm. The rate of positive surgical margins was 17.3 % (73/423) in pathologic stage T2 and 34.6 % (226/646) in all cases. The BSMs were positive in 10.1 % (66/646) of cases. A logistic regression analysis revealed that PML was significantly correlated with BSM positivity in all cases (odds ratio [OR] 1.080, p = 0.026). In particular, they had a stronger correlation with pathologic stage T3 or higher (OR 1.1143, p = 0.004). PML was an independent predictor of BSM positivity (OR 1.113, p = 0.046) in pathologic stage T3 or higher, as were preoperative prostate-specific antigen, prostate size, and pathologic stage. Cases with 10 mm or higher PML had significantly more BSM positivity than cases with <10 mm PML (35.9 vs. 20.1 %, p = 0.012).
  
  
  CONCLUSIONS
  Protrusion of the median lobe measured using preoperative MRI was significantly correlated with positive BSMs during RALP. Surgeons should pay more attention to patients with 10 mm or higher PML and advanced stages.
authors.affiliation: Department of Urology, Seoul National University Bundang Hospital, 82, Gumi-ro 173 Beon-gil, Bundang-gu, Seongnam, Gyeonggi-do, South Korea.
authors.forename: Chang Wook
authors.initials: CW
authors.lastname: Jeong
authors.forename: Sangchul
authors.initials: S
authors.lastname: Lee
authors.forename: Jong Jin
authors.initials: JJ
authors.lastname: Oh
authors.forename: Byung Ki
authors.initials: BK
authors.lastname: Lee
authors.forename: Jung Keun
authors.initials: JK
authors.lastname: Lee
authors.forename: Seong Jin
authors.initials: SJ
authors.lastname: Jeong
authors.forename: Sung Kyu
authors.initials: SK
authors.lastname: Hong
authors.forename: Seok-Soo
authors.initials: SS
authors.lastname: Byun
authors.forename: Gheeyoung
authors.initials: G
authors.lastname: Choe
authors.forename: Sang Eun
authors.initials: SE
authors.lastname: Lee
mesh_terms: D000368:Aged; D006801:Humans; D010535:Laparoscopy; D016015:Logistic Models; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D018365:Neoplasm, Residual; D016017:Odds Ratio; D011467:Prostate / Q000473:pathology*; D011468:Prostatectomy; D011471:Prostatic Neoplasms / Q000473:pathology / Q000601:surgery*; D012189:Retrospective Studies; D012371:Robotics; D016896:Treatment Outcome